If you have a family doctor they can sometimes direct you to a counsellor. There is also United Way and groups of that nature. Some companies have employee assistance plans for their employees to consult for guidance with problems at home/with children/marriage, etc. These plans are totally confidential, that is, the counsellor is outside the workplace and all that is reported back to the company is the number of persons they have seen from the company - no personal information is actually given to your company.
My company and my husband's both have that service. I work for an American company so I'm assuming you folks would often have the same benefits.
Good question. I'd start with your church and see who they might recommend. If you don't go to church, then you will just have to call a few and see if you can get a "feel" as to your comfort level with them.
DH and I are pretty good at counseling and have helped and talked to a few friends and they applied some of our suggestions and are happier.
I've been doing internet searches for counselors, and that has lead me to some articles about how some counselling methods can be damaging to marriages. Very scary. I would like to go to a Christian counselor because it seems like the value system would be evident up-front, but my DH is quite agnostic at this point in his life and I don't know think he would be comfortable with counselling framed by religious beliefs. I also just really don't want a counselor who will tell us to get divorced to find personal fulfillment!